BIOTREATMENT OF A FOOD INDUSTRY WASTEWATER AS AFFECTED BY PH

CONTRERAS E.; ZARITZKY N.

Campeche, Mexico

Simposio; Fifth Latin American Biodegradation and Biodeterioration Symposium (LABS5); 2004

Abstract   Food processing industries discharge wastewaters characterized by large amounts of organic compounds. The activated sludge process is a widely used method for treating industrial and domestic wastewaters. Sphaerotilus natans is filamentous microorganism that causes a common problem in these plants known as filamentous bulking. In the present work the effect of pH on the growth kinetics of Sphaerotilus natans using a food processing industry wastewater was studied. Biodegradation batch experiments were performed in a 1-liter working volume reactor; the culture medium contained citrate (limiting substrate) and ammonia as carbon and nitrogen sources respectively. The tested pH ranged between 6 to 9 and it was controlled (±0.1) by the addition of sulfuric acid. The obtained results showed that the maximum specific growth rate (µmax) was a bell-shaped curve with a maximum value between pH 7 to 8; besides the maximum specific oxygen uptake rate (qO2max) decreased as the pH increased. A mathematical model that interprets the effect of pH on the biodegradation parameters was proposed.